I'm trying to replicate some behavior from other engines in T3D's animation system, specifically threads and blends. I have a walking animation set, in 4 directions, and the player has no pose for the arms. However, i also have a single keyframe of the character holding a sword and another a bow. How can i blend that single-frame animation (pose) of the character aiming a weapon with the movement animations? I really don't want to create the same walking animations over and over again, for each kind of weapon i end up creating (since it's a medieval game, i have a shitload of poses to work on: swords, bows, crossbows, magic spells, etc.

I don't think you got the issue. I don't have an animation for each weapon type, just a pose for the aim position. I want to blend the positions defined in that pose with the rest of the keyframes in the walk animation, dynamically creating the walking animations for each weapon type.

You don't need animations for that at all, you don't blend hand animations with walk animations, since they are automatically blended, since you only animate the legs for walking and only the hands for aiming.
In Torque you have "Head" and "Look" sequence, those define head movement and look direction, so you already have 3 animations that are blended into one or over other animations, look it up here: http://docs.garagegames.com/torque-3d/o ... rimer.html

You don't need "thousands" of animations, just one for each state. So you have one pose without weapon and one with weapon, this makes two.
So you will have the root pose, which will be the position of the character without weapon, then you make another sequence called "weapon_root" or so, this will be the root when you holding that weapon, the animation will have the hands moved into place, nothing else and the rest of the animations are blended in from other sequences.